Development of a Production Scheduling Model in a Hybrid MTO/MTS Production System Considering the Demand for Spare Parts

Abstract

In this paper, a new mathematical model for production scheduling in hybrid Make-to-Order (MTO)/Make-to-Stock (MTS) systems is presented, incorporating the possibility of selling semi-finished parts. The objective of this research is to develop an optimization method that not only reduces production time and operational costs but also provides precise scheduling of start/end times for each machine’s tasks and machine utilization durations throughout the process. The proposed model is formulated as a Mixed-Integer Linear Programming (MILP) framework and enhances system efficiency by simultaneously managing MTO order demands, MTS demands, and independent demands for semi-finished parts in both MTO and MTS systems, while minimizing resource wastage. Simulation and sensitivity analysis results demonstrate that the model can significantly improve scheduling accuracy and optimize equipment utilization. The evaluation of the model was conducted using simulated data. This approach has broad applications in industries such as automotive and electronics and can support strategic decision-making in production management.